Bob,
I built one of these Advantages for a customer once (I think in 1996), pretty nice boat acyually, fun to drive, the only thing I didn't like about it was the lack storage. Well built but the one we did was not rigged because he bought it as a hull and interior, we bought the trailer and put a Marine Power 454 and a Dominator in it, ran about 65 MPH with a little bit of tweaking and turned like it was on rails...
That is if this is called the 20.5 Open (I think it said "River Cruiser"). BTW, they carpet literally everything.
GT